1. Technical Field
The present invention relates to a multilayer film, an electrooptic device, an electronic apparatus, and a process for forming the multilayer film.
2. Related Art
In recent years, film-forming techniques employing droplet discharge methods, i.e., inkjet methods, have been used in the production of interconnections and functional elements. In a known film-forming technique, a functional film is formed by disposing a liquid (functional liquid) containing a functional material on a substrate with a drawing device such as an inkjet printer to form a pattern; and performing drying or the like on the disposed functional liquid. Such a film-forming technology can be applied to high-mix low-volume production and is significantly effective.
In the production of a functional element or the like by the film-forming technique, a plurality of types of functional films can be laminated by successively repeating the drawing and drying steps. For example, JP-A-2004-63138 discloses a process for producing a functional element including a hole-transporting layer and a luminescent layer by the droplet discharge method. Furthermore, JP-A-2003-315813 discloses a process for producing an interconnection formed of an underlying layer and a conductive layer by the droplet discharge method.
In such a multilayered functional film (hereinafter, referred to as a “multilayer film”), the adhesion and contact properties between the layers may significantly affect reliability and characteristics. For example, in the interconnection formed of the two layers, the adhesion between the layers affects interface resistance and delamination resistance between the layers. In the luminescent element, the luminescence occurs in the vicinity of the interface between the hole-transporting layer and the luminescent layer in the luminescent element. JP-A-2002-110352 and Japanese Patent No. 2,773,297 disclose that the contact area between the layers is closely related to the luminous efficiency.
However, the known process for forming the multilayer film by the droplet discharge method is not sufficient for the improvement of the adhesion and contact properties between the layers.